Even if we are careful, at some point we will probably damage our favourite clothes in some way. That includes when we throw a jumper into the washing machine only to have it emerge smaller and misshapen. Not all shrinkage is reversible, but prompt action may save at least some of your clothes.
Why do clothes shrink?
Broadly speaking, clothes shrink when the tension holding fibres together is loosened. This can happen because of a combination of heat, moisture and mechanical strain or agitation, all of which can be found inside a washing machine.
Shrinkage varies between fabrics. For instance, womens Aran cardigans like those available from shoparan.com, are made of pure wool, which has small scales on its surface that expand, move and eventually stick together in the conditions of a washing machine cycle. Synthetics such as polyester are less likely to shrink, both because they have longer, less twisted fibres and because they are more resistant to heat and moisture.
How to avoid shrinkage
To minimise the risk of shrinkage, reduce the temperature of the washing cycle and dry clothes on a line rather than in a tumble drier. You could also wear more second-hand clothing, which has probably already shrunk as much as it is going to.
How to unshrink
If your clothes do end up shrinking, steam may help. At home, this is most easily done with an iron. Press it down to maintain tension until the fabric cools again. This may only be a temporary measure, and it will not always work.
Other methods, depending on the material, may involve soaking in baby shampoo or vinegar before stretching out to the desired size and shape and fixing in place until it dries. Sometimes, taking to a professional dry cleaner is the best option.
It is best to try and avoid situations where your clothes are at risk of shrinkage in the first place. But if it does happen, the most important thing to do is expose it to steam. This may be the only way to rescue your jumper, though success is not guaranteed.